docs: def get_language_from_request(request):
      """Return the most obvious language according the request."""
      language = request.GET.get('language', None)
      if language:
          return language
  
      if hasattr(request, 'LANGUAGE_CODE'):
          lang = settings.PAGE_LANGUAGE_MAPPING(str(request.LANGUAGE_CODE))
          if lang not in LANGUAGE_KEYS:
              return settings.PAGE_DEFAULT_LANGUAGE
          else:
              return lang
      else:
          return settings.PAGE_DEFAULT_LANGUAGE